#include <iostream>

int main()
{
    int *intPtr = nullptr;       // 整数指针
    double *doublePtr = nullptr; // 双精度浮点数指针
    char *charPtr = nullptr;     // 字符指针
    void *voidptr = nullptr;

    std::cout << "Size of int pointer: " << sizeof(intPtr) << " bytes" << std::endl;
    std::cout << "Size of double pointer: " << sizeof(doublePtr) << " bytes" << std::endl;
    std::cout << "Size of char pointer: " << sizeof(charPtr) << " bytes" << std::endl;
    std::cout << "Size of void pointer: " << sizeof(voidptr) << " bytes" << std::endl;

    return 0;
}